As Stephen Colbert prepares a final sendoff for the Late Show on CBS May 21, the program is planning a slew of late night A-listers next week. David Letterman, who launched the program in 1993 before handing the reins to Colbert in 2015, will be a guest on the Thursday, May 14 episode. Monday’s episode, May 11, will feature a reunion of the “Strike Force Five,” when the active late night hosts all teamed for a podcast to benefit striking writers in 2023. Jimmy Fallon, Jimmy Kimmel, Seth Meyers & John Oliver will appear on the Late Show that evening. Kimmel will be in town for Disney’s upfront presentation, scheduled for Tuesday. Letterman, meanwhile, called CBS executives “lying weasels” about the decision to cancel the show in an interview earlier this week. He has only made one appearance on the show since stepping down, back in 2023.…